Medical pad systems for systemic cooling and/or heating of patients are known. Typically such systems include a pad that is placed on the patient. For example, the pad might be placed on the patient's torso. A fluid, such as water or air, is then circulated through the pad. Thermal energy is exchanged between the patient and the circulated fluid to cool or heat the patient. For example, water or air at an appropriate temperature below the desired temperature of the patient may be circulated through the pad to absorb heat from the patient and thereby achieve systemic cooling.
The therapeutic use of systemic cooling for a variety of conditions has been investigated. Of particular interest, it has recently been discovered that rapid systemic cooling of stroke and head trauma patients may have significant therapeutic benefits. Stroke is a major cause of death and neurological disability. Recent research suggests that even though a stroke victim's brain cells may lose their ability to function, the cells do not necessarily die quickly. In fact, brain damage from a stroke may take hours to reach maximum effect. Neurologic damage may be limited and the stroke victim's outcome improved if a neuroprotectant therapy is applied within this time frame. As a result of vehicle crashes, falls and the like, many people suffer traumatic brain injury (e.g. impairment of cognitive abilities or physical functioning). Elements in the genesis of traumatic brain injury are now understood to overlap with elements in the genesis of neurologic damage in stroke victims. Delayed secondary injury at the cellular level after the initial head trauma event is now recognized as a major contributing factor to the ultimate tissue loss that occurs after brain injury.
One neuroprotectant therapy that may be applied early in the treatment process to stabilize and reduce ongoing cellular damage is hypothermia. Studies have shown that treatment with mild hypothermia, defined as lowering core body temperature 2-3.degree. C., confers neuroprotection in stroke victims, and may hasten neurologic recovery and improve outcomes when applied for twenty-four to seventy-two hours in cases of traumatic brain injury.